In a Federal Aviation Administration (FAA) document made public on Monday, the airspace regulatory body described (indirectly) Amazon's delivery efforts as illegal.

In a Federal Aviation Administration (FAA) document made public on Monday, the airspace regulatory body (indirectly) described Amazon's delivery efforts as illegal. In the 17-page clarification, the FAA essentially splits the drone issue into two categories: "hobby or recreation" and "commercial use." Since 2007, the FAA has considered commercial drone use to be illegal; seven years later its stance hasn't changed.

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When describing what constitutes as "commercial use," the FAA used the not-so-subtle example of "delivering packages to people for a fee." This no doubt was influenced by Amazon's big reveal in December that the company was pursuing drone delivery with a new service called Amazon Prime Air.

The FAA also tried to cover any loopholes with a quick footnote: "If an individual offers free shipping in association with a purchase or other offer, FAA would construe the shipping to be in furtherance of a business purpose, and thus, the operation would not fall within the statutory requirement of recreation or hobby purpose." Translation: Don't even try it, Amazon.

Amazon has always known that its schedule for debuting Prime Air depends upon when the FAA would establish favorable rules and regulations allowing for commercial unmanned aerial vehicles. And this news doesn't mean Amazon Prime Air is permanently grounded as the FAA will re-evaluate its stance on small commercial drones later in the year with plans to put enforceable rules in place by the end of 2015, according to according to Ars Technica.

Legalizing commercial drone use, for delivery or otherwise, still seems more a question of "when," not "if." In February, Business Insider estimated that of the $98 billion that will be spent on aerial drones in the next decade, 12 percent will be commercial. Military use will make up the lion's share of that money. But many commercial projects have military origins—just think of GPS and the internet. Really, the FAA seems to be biding time until it figures out exactly how to handle commercial UAVs. Until then, it's a no-fly zone.

Update:CNET reports that Amazon doesn't see this new ruling as interfering with their plans moving forward. An Amazon spokesperson stressed that these rules only affect hobbyists and model aircraft, and not a commercial entity like Amazon. The company still awaits the FAA's ruling in 2015 that will more directly affect Prime Air.